Package org.apache.storm.trident.state

Interface State

All Known Subinterfaces:
MapState<T>, ReadOnlyMapState<T>, ReadOnlySnapshottable<T>, RemovableMapState<T>, Snapshottable<T>
All Known Implementing Classes:
DebugMemoryMapState, HdfsState, HiveState, JdbcState, JmsState, LRUMemoryMapState, MemoryMapState, NonTransactionalMap, OpaqueMap, ReadOnlyState, RedisClusterState, RedisState, SnapshottableMap, TransactionalMap, TridentKafkaState, TridentReach.StaticSingleKeyMapState, WindowsState
public interface State
There's 3 different kinds of state:

1. non-transactional: ignores commits, updates are permanent. no rollback. a cassandra incrementing state would be like this 2. repeat-transactional: idempotent as long as all batches for a txid are identical 3. opaque-transactional: the most general kind of state. updates are always done based on the previous version of the value if the current commit = latest stored commit Idempotent even if the batch for a txid can change.

repeat transactional is idempotent for transactional spouts opaque transactional is idempotent for opaque or transactional spouts

Trident should log warnings when state is idempotent but updates will not be idempotent because of spout

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    beginCommit(Long txid)
     
    void
    commit(Long txid)
     

  • Method Details

    • beginCommit

      void beginCommit(Long txid)

    • commit

      void commit(Long txid)